"He made some mistakes. We expect better from him," Haslam said Saturday morning after the Browns first preseason practice. "I'm sure he'll perform. We're anxious to see what he can do on the field, which is what really counts."

Haslam rattled off a list of the most famous pro athletes, from LeBron James to Peyton Manning to Tom Brady to Derek Jeter, as players Manziel should try to emulate as huge stars who deftly handle the huge spotlight, even in their lives away from their sport.

"The really great athletes make their news on the field, not off the field," Haslam said.

Manziel said he agrees with Haslam's message. For the second consecutive day, Manziel on Saturday reiterated that he learned this summer that he needs to project a better image as a professional athlete. Manziel was a social media star this offseason after partying with celebrities like Drake and Justin Bieber and was frequently photographed swigging alcohol at nightclubs in Austin, Tex., Hollywood and Las Vegas.

"Luckily for me I'm living out my dream of playing in the NFL and having a ton of fun. My dream has come true, and I finally have the chance to get some down time and celebrate that with my family and friends. I mean, this is the greatest life I could have ever imagined for myself, and I'm loving that," Manziel said. "Will I continue to get better being a professional and learn lessons about life? Of course. I'm 21 years old. Age is not an excuse, but I need to mature, and I have done some immature things, but moving forward I'm going to try to mature, and try to handle myself better as a professional."